package day20.java1;

import java.net.InetAddress;
import java.net.UnknownHostException;

/*
 * 网络通信的第一个要素：IP地址。通过IP地址，唯一的定位互联网上一台主机
 * InetAddress:位于java.net包下
 * 1.InetAddress用来代表IP地址。一个InetAdress的对象就代表着一个IP地址
 * 2.如何创建InetAddress的对象：getByName(String host)
 * 3.getHostName(): 获取IP地址对应的域名
 *   getHostAddress():获取IP地址
 */
public class TestInetAddress {
	public static void main(String[] args) throws Exception {
		//创建一个InetAddress对象：getByName()
		InetAddress inet = InetAddress.getByName("www.atguigu.com");
		//inet = InetAddress.getByName("42.121.6.2");
		System.out.println(inet);
		//两个方法
		System.out.println(inet.getHostName());
		System.out.println(inet.getHostAddress());
		//获取本机的IP:getLocalHost()
		InetAddress inet1 = InetAddress.getLocalHost();
		System.out.println(inet1);
		System.out.println(inet1.getHostName());
		System.out.println(inet1.getHostAddress());
	}
}
